The present embodiment relates to a sinterable composite electrolyte compound, a sintered composite electrolyte, a method for producing a sintered composite electrolyte, and the use of the sintered composite electrolyte in a fuel cell, preferably a solid oxide fuel cell, an exhaust gas probe or a high-temperature gas sensor, and a fuel cell, preferably a solid oxide fuel cell, exhaust gas probe or high-temperature gas sensor containing the sintered composite electrolyte.
For reasons associated with the manufacturing process, an SOFC monobloc green body manufactured by Additive Layer Manufacturing (ALM) or non-conventional 3D manufacturing processes such as weaving technology must be produced directly from all required, electrochemically active layers. Accordingly, all of the layers or materials (anode, electrolyte, cathode), which may for example consist of three or as many as eight layers or materials, must be co-sintered at exactly the same temperature and for exactly the same bonding time. Since the materials become denser as the sintering temperature and bonding times increase, and remain more porous at lower temperatures, the need for a gas-impermeable electrolyte is in direct conflict with the need for electrodes having the highest possible degree of porosity. An electrolyte with a density greater than 5.90 g/cm3 is considered gas-impermeable for the purposes of SOFC technology.
Thus, it would be desirable to provide a sinterable composite electrolyte compound that can be used for a fuel cell, preferably a solid oxide fuel cell, an exhaust gas probe or high-temperature gas sensor and has good ion-conducting capability (O2−) in the sintered state. It would also be desirable to provide a sinterable composite electrolyte compound that can be processed by Additive Layer Manufacturing (ALM) or non-conventional 3D manufacturing processes such as weaving technology. Additionally, it would be desirable to create a sinterable composite electrolyte compound that still becomes gas-impermeable at sintering temperatures Tsinter ≤1300° C. and with a bonding time tbond<5h, yielding a sintered product having a density ≥5.9 g/cm3, which is also capable of thin dimensioning, i.e. has the highest possible mechanical stability.
The problem addressed by the present embodiment is therefore to provide a sinterable composite electrolyte compound that can be used for a fuel cell, preferably a solid oxide fuel cell, an exhaust gas probe or high-temperature gas sensor, and has good ion-conducting capability (O2−) in the sintered state. This also addresses the further problem of ensuring that the sinterable composite electrolyte compound can be processed by Additive Layer Manufacturing (ALM) or non-conventional 3D manufacturing processes such as weaving technology. This also addresses the problem of ensuring that the sinterable composite electrolyte compound can be processed at sintering temperatures Tsinter≤1300° C. and for a bonding time tbond<5 h and results in a gas-impermeable electrolyte composite that has a density ≥5.9 g/cm3 but at the same time is capable of thin dimensioning, i.e. has the highest possible mechanical stability.
These problems are solved with the objects defined in the claims. Advantageous embodiments are given in the dependent claims.